Optimum Trim - Destination One Design
PART TWO OF SAIL’S NEW SERIES
ON SAIL TRIM: LEARN HOW TO
SET UP, TRIM, AND GYBE AN
ASYMMETRIC CRUISING SPINNAKER
BY JOSH ADAMS
The limiting factor of any asymmetric is the point at
which the sail is tacked. You have to sail fairly high reaching angles if the spinnaker is tacked near the bow, as
most cruising chutes are. Because a small amount of sail
area is projected forward and to windward, the mainsail
blankets the spinnaker at deep angles.
The Tartan 33’s spinnaker sets
up well with the tackline eased
roughly 6 inches above the bow
pulpit. Note the sail’s ample
depth for offwind power.
OU’RE 10 MILES TO WINDWARD OF YOUR CRUISing destination. The forecast calls for light
winds from the same direction over the course of
the afternoon. You have time to reach your anchorage.
What’s your move? Do you fire up the engine? Go
wing-on-wing? The savvy cruiser has an ace up his
sleeve: Pop the chute!
A well-rigged asymmetric cruising spinnaker should be easier to handle than a racing chute. Racers do a lot of different
things with an A-sail, flying it off a bowsprit or a mastmounted pole, executing sailhandling techniques that require a lot of hands, and sailing the boat at precise angles. Cruisers
also want to get there faster, but only if the extra sail power
requires minimal handling.
You can fly an asymmetric on any cruising sailboat.
Adding one to your inventory requires some hardware on
deck to tack the sail, a few blocks near the bow to lead the
tackline aft, spinnaker sheets, and possibly a twing on each
side of the boat to fine-tune the sheet-lead angle. Most cruisers will want to install a spinnaker snuffer (also known as
a sleeve or sock), the ultimate aid to handling the asymmetric.
A well-designed snuffer can contain the sail in a matter of
To learn how to properly set up and trim a cruising asymmetric, I went sailing with Dave Flynn of Quantum Sail Design Group in Annapolis, Maryland, and Rege Becker, from
Solomons Island, on Becker’s 24-year-old Tartan 33, Moving
Target. The first thing I noticed on his well-equipped cruiser
were its 5/16-inch-diameter Spectra spinnaker sheets. They are
lightweight, low stretch, and comfortable to handle. He’s
also rigged the boat with twings and an ATN spinnaker sleeve
on his 710-square-foot asymmetric.
PHOTOS BY WALTER COOPER
[SNUFFER CONTROL LINE]
An asymmetric can be
a cruiser’s downwind
weapon. The chute on
Moving Target, a Tartan
33, is tacked at the
bow, which limits the
amount of sail area
projected forward and
to windward. Sail
higher angles to
compensate for this.
SAIL September 2005
[SPINNAKER SLEEVE] The
lightweight ATN spinnaker
sleeve is controlled by a
continuous line. It’s either
on (sleeve max down) or off
(hoisted to the head of the
sail). Both parts of the line
should be cleated at the
mast once the sleeve is set.
You need someone on the
bow to handle the sleeve.
[TACK CONTROL] The
tackline can be adjusted
from the cockpit with
one hand before it gets
loaded up with wind
On a cruiser with a large coachroof, there is limited room on
deck for sailhandling between the cockpit and the mast.
Lead all controls aft, except the control lines for the spinnaker
snuffer. On Moving Target, the tackline and the sheet can be
adjusted from the cockpit. One crewmember should handle
the snuffer from the bow; remember to furl the jib.
[TWING] The cruising chute on the Tartan needs a twing to
deflect the sheet down and give the leech the proper amount of
twist. Becker’s twing setup includes a snatch block (which
allows you to add the twing while the chute is flying), a block
at the rail, and a block/cleat at the rail near the cockpit.
[TACKLINE] Becker rigs his spinnaker tackline with two turning
blocks—one fastened on the toerail, the other at the base of the
pulpit. The Spectra tackline leads aft to the cockpit.
September 2005 SAIL
Through trial and error on Moving Target, we discovered that
even though it is slower, the snuffer gybe is the easiest and
requires the fewest hands. It can easily be done with two
people—one person steering and the other handling the sail—
but three is best. Use the snuffer to rotate the sail around the
headstay; this helps avoid wraps and tangling sheets.
 What’s the rush? Use the snuffer in a gybe. Step one in a
snuffer gybe is sending one person to the bow to lower the
 Once the sail is rotated and clear of the gear at the pulpit,
hoist the snuffer collar.
 With the sail under control, guide the snuffed sail around
the headstay, making sure the sheet (yellow line) is eased. The
helmsman can turn the boat to the new gybe; maintaining a
deep course will keep things stable for the bowman.
 Wait until the collar reaches the head of the sail before
trimming the sail on the new gybe and steering a higher course.
The bowman’s last job is to fasten the snuffer control line to
SAIL September 2005
On a raceboat rigged with a bowsprit or mast-mounted pole,
it makes sense to run the sheets inside—between the headstay and the luff of the A-sail. But it’s best to lead the sheets
outside the luff on an asymmetric that is tacked at the bow,
because of tight space between the headstay and the sail. The
downside of this arrangement is that the clew (and sheet)
must travel farther when gybing the sail.
 A good outside gybe requires a trimmer ready to haul
several yards of sheet and a soft touch by the helmsman. The
correct rate of turn (adjust depending on wind strength) is a
slow turn at the beginning, turning faster (higher) as the chute
fills on the new gybe.
 As the helmsman bears away and prepares to gybe, let the
sheet run free. Getting the clew forward as quickly as possible
will make it easier to haul it aft on the other side.
 During this gybe, Dave Flynn trims while facing backward. It
gives him more room to operate the sheets in the Tartan’s
relatively small cockpit.
 As the chute fills, steer the boat on a tighter angle to build
speed. Less height is needed as the wind builds. Communication
helps; the trimmer should inform the helmsman how much
pressure is in the sail. The trimmer should return to his normal
position, where he can see the luff of the sail.
September 2005 SAIL